1. Field of the Invention
The present invention relates to a dipeptide sweetening composition. More particularly the present invention is concerned with a dipeptide sweetening composition in which dipeptide sweeteners are kept stable against heat or enzymes, and which can give the foods a long lasting flavor of a clear sweetness.
2. Description of the Prior Art
Dipeptide sweeteners such as .alpha.-L-aspartyl-L-phenylalanine-methylester are generally known as low calorie sweetening agents which have the quality of possessing a clear initial taste without leaving an unpleasent bitter taste, as others such as saccharin. Problems have arisen, however, in that many of them have less stability against heat or enzymes in the aqueous condition than other well-known sweeteners such as sugars, polyols and synthetic chemicals like cyclamate and saccharin.
Because of this reason, the applications of dipeptide sweeteners to processed foods, the production of which indispensably requires a prolonged exposure to moist heat, are greatly limited. Their use for fermentation foods is also restricted, because enzymatic action causes a loss of sweetness of the dipeptide sweeteners.
While dipeptide sweeteners are known are suitable sweetening agents giving a long-lasting sweetness to chewing gums (U.S. Pat. No. 3,943,258), there have arisen several problems, i.e., the stability of the dipeptide sweeteners during the manufacturing process and storing period, wherein they are kept under conditions of relatively high pH and temperature, and in contact with water, the quality of sweetness of the sweeteners during the long-lasting period of chewing, and also the longer-lasting sweetness than that of the chewing gums containing dipeptide sweeteners alone or in combination with other sweetening agents.
Measures have been taken to stabilize flavoring materials against heat or enzymes, examples of which are fat-coated 5'-nucleotide flavoring agents, and gelatin encapsulated spices or flavoring agents. These measures, however, cannot always give efficient results in that the strength of coatings or capsules is not sufficient. Concerning the improvement of the physical properties of the dipeptide sweeteners, some kinds of dextrin are employed to encapsulate the dipetide sweeteners. This improvement, however, is directed to obtain stability of dipeptide sweeteners in an aqueous condition, and not against heat or enzymes.
A need therefore continues to exist for a dipeptide sweetening composition which can be kept stable against heat and enzymes, and give to processed foods in which it is employed, a sufficient sweet taste as well as providing a long-lasting sweetness when employed in chewing foods.